Electrical compensator



Aug. 3, 1937. BATCHELDER 2,083,580

ELECTRICAL COMPENSATOR 7 Filed Jan. 6, 1955 3 Sheets-Sheet l FIG. I

5 LINE INVENTOR LAURENCE BA TCHELDER BY 23,144 M ATTORN EY 1937- L. BATCHELDER 2,088,580

ELECTRICAL COMPENSATOR Filed Jan. 6, 1935 3 Sheets-Sheet 3 "u ldn u'u'u INVENTOR FIG. 5 LAURENCE BATCfi/[LDER BY /ZMW ATTORNEY Patented Aug. 3, 1937 I UNITED STATES PATENT OFFICE 2,088,580 v ELECTRICAL COMPENSATOR Laurence Batchelder, Cambridge, Mass., assignor to Submarine'Signal Company, Boston, Mass., a corporationot Maine Application January 6, 1933, Serial No. 650,535

Claims. (01. 177-386) The present invention relates to electric com-' able to preserve the continuity of the impression D sators. to the observer. The result was that a compen- Eiectric compensators have been known for a sator of fewer sections could be built and that considerable time and have been used among both the intermediary and final lines could be other purposes for the directive reception of unmade to have the same time lag. derwater noises and signals. Considerable de- In the present invention I retain all the advelopment along these lines was first made durvantages obtained by the "compensator disclosed ing the World War when the use of the so-called in the above-mentioned copending application multispot compensation was first evolved. Elecand in addition provide a means whereby the 10 tric compensators were used with a group of renumber of inductive section elements may be re- 10 v ceivers submerged in the water, either mounted duced.

within the vessel or carried over the side, for The present invention employs a compensator detecting the presence of other vessels such as switch which utilizes a pair of bridging coils enemy submarines or warships. Compensators which it connects in parallel with the normal used in this manner have also found applicacoils of the retardation line. Consequently it is 15 tion along commercial lines and have been used possible to obtain a mid-series termination of the successfully in preventing collisions between vesline as well as the usual mid-shunt termination sels as well as determining the direction of some when only a ,single two-terminal inductance is known source of sound. used in each section. Because of the alternate In a compensator of the present type which mid-series and mid-shunt terminations, it is pos- 20 may be called a group compensator, the groups sible to shift the compensation in steps of oneare first individually compensated and then comhalf section instead of a whole section. Thus pensated as a whole between the two indicating for a given size of step in compensation the numor telephone devices in the same general way as her of coils in the binaural lines may be reduced to in the prior art. In the compensators ofthe .half the number previously used. 25 prior art having aso-called binaural line, that is In the case of maximum lines the number of the line which compensates each group for a final coils and condensers will not be reduced but an balance, a switching arrangement is used which improper termination will be avoided. The presopens the line successively at different sections. ent invention, therefore, not only increases the The electrical contacts at the points where these accuracy of the compensator, but also reduces its 30 openings occur-are often poor, because of dust or size. smallparticles which come between the contact- These and other features will be more clearly ing surfaces with the result that some resistance understood from the description of an embodiis set up in the circuit. This increases the rement of the invention illustrated in the drawings sistance on the coilside of the lineand produces annexed hereto. J a distortional effect which reacts very unfavor- In the drawings Fig. 1 shows a schematic wirably in creating false observations and inaccurate ing diagram of the compensator including the rebalances when making a compensator setting. tardation lines and the switch; Fig. 2 shows a Besides this, the added resistance increases the development of a part 'ofthe switch controlling 40 attenuation of the line. the binaural line; Fig. 3 shows a development 40 In my copending application SerialNo. 600,191, of a part of the switch controlling the maxifiled March 21, 1932, I showed how these diflimum line; Fig. 4 shows a modification of Fig. 3; culties could be overcome by employing a switch and Fig. 5 shows schematically a modification of arrangement in which the line is varied at the Fig. 1.

common side and the line is therefore preserved In the present case the invention is illustrated 45 intact while the switch is being moved from secas applied to a so-called six-spot system, but any tion to section. number of spots may be used and, in fact, other This switching arrangement had the further arrangements than those indicated in the drawadvantage that it was possible to increase or deings may be employed, as, for instance, a circrease the length of the line a half section at a cular group or a group forming other configura- 50 time so that the sections could be made twice the tions in a plane or in a three-dimensional space. size that otherwise could beused. The sections In the embodiment herein described six hydrocould therefore be made twice the size necessary phones are installed on the starboard side of the to produce the maximum change of retardation vessel and six hydrophones on the port side. Se-

in the motion of the compensator switch allowle ctor switches are then provided so that the six 55 starboard hydrophones may be employedto listen to sounds approaching from the starboard side of the vessel or the six port hydrophones may be employed to listen to sounds approaching from the port side of the vessel, or three of the starboard hydrophones and three of the port hydrophones may be employed as a cross base to listen to sounds coming from ahead.

In Fig. 1 the coils of the port receivers are represented by I'p, 2'10 6'12 while the coils of the six starboard receivers are indicated as Is, 2's 6's. The hydrophones used in connection with this compensator are matched directly with the lines on which the sound energy is impressed. The direct current flux excitation is supplied in series groups of three; the switches I3 and 9 applying the potential of the battery I3 across the common It and each of the groups of windings I2. A selector switch I is provided which has three positions: a bow position as indicated in the position shown in Fig. l, a port position when rotated to the left and a starboard position when rotated to the right. For

- indicated at the top of the the bow position it will be noted that there is a choice of 'the use of the forward groups or the aft groupsof three receivers. This choice may be eilfected by the, jumper connectors I and 8 which connect the switch arms9 and It to the connecting points F on the left or A on the right.

The jumpers I and 8 are preferably fixed when the installation is made for the best choice on the vessel and thereafter are not changed unless it is especially desired to do so. In the position of the jumpers indicated in Fig. 1, it will be noted that the forward group F connecting with Mr, 2'2), ,3'p and I's, 2's and,3s. is used. In the position of the jumpers on the right contact points A the receivers 4'1), 5'1: and 6'1) and 6's, 5's and 6's would be connected to the compensator. The switch 9 in its downward position is connected with the two switch points whose combination is designated 93. In this relation the jumpers 8 sloping to the left energize the coils in the receiversIp, 2'1), 3'1) and I's, 2's and 3's. With the jumpers 8 in the other position the rear or aft group of receivers would be energized.

In the position for bow compensation, as indicated by the position of the switch I5, the end switch arms I I and I I' com ect the receivers with fixed compensation'directly to the binaural line 6. In the position shown in-Fig. 1 the receiver I'p is connected to the C-line at its left end. The receiver Z'p is connected through the switch point 23 at the end of the fixed or F-line while the receiver 3'9 is connected at the right end of the C-line. The energies from the receivers thus compensated in a fixed fashion are impressed by means of the connecting lead I6-to' the common of one-half of the B-line as indicated by the numeral I'I ap-- plied to the right half of the ring I8. 1

Similarly the starboard half group is connected to the left connector I9 of the ring I8 by means of the connecting lead 2|.

\ sition of the switch I8 connects to the left end of the C-line while the'receiver 3's connects.

In this case the starboard receiver I's connected through the 8B 100- 2,oas,seo

of the B-line and similarly also one terminal of the phone 26 is connected to the other extreme end of the B-line.

The description above illustrates the switching arrangement for the so-called bow position.

In the port and starboard positions the switch arm I5 is moved to the left and right, respectively, that is to the left for the port position and to the right for the starboard position. In the port position the receivers Ip, 2'p and 3'7) are connected to the left end of the C-line, the end of the F-line and the right end of the C-line, respectively. The switch II in the position at the left connects the F-line to the switch contacts 62, 20 and 63 by means of the lead 21. Similarly the switch II' in the position II'p connects the F-line to the switch contacts 64, 30 and 65 by means of the lead 28. The switch contacts 62, 28 and 63 and 66 30 and 65, respectively, unite the impulses passing through each F-line and its corresponding C-line at the correct points to produce the desired compensation to compensate for the difference in time of arrival of the wave energy at the receivers of each group.

As will be noted, the switch contacts 62, 20 and 63 and 64, 30 and 65 are adapted to move over the contact studs .3I to 36', inclusive, and 31 to 42'; inclusive, respectively, each stud connecting to a different point on the left and right C-lines, respectively. The contact switches 62, 2'0 and 63, and 64, 38, and 65 move simultaneously on the same mechanism as the ring I8 and the switch brushes 43, 51 and 44: the position of the contact switches 62, 20 and 63, and 64, 38 and 65 adjusting the compensation of the C-lines and the position of the ring I 8 and the contact brushes 43, 51 and M adjusting the compensation of the B-line.

As indicated in Fig. l the energy from the left F- and C-lines is fed into the B-line by the two conductorspomprising the lead I6 together with a' portion I1 of the ring I8 and'the brushes M and 51 while the energy from. the right F- and C-lines is fed into the B-line by means of the conductors 22 and Ill together with the portion I9 of the ring I8 and the brushes t3 and 5'|. The ring I8 and the brushes 63, 51 and M move simultaneously breaking the B-line each half section in its motion. This is accomplished as follows:

The B-line is composed of series inductances 46, 66, etc., which with the condensers 58, 58, etc., form the sections of the line. The con.- densers 58 are connected between the series inductances and the common. The line sections may be considered as either T sections or 1r sections, and are, in fact, first one and-then the other, depending upon the switch positions. It should be noted, however, that whether the sections are considered to be 1r or T sections, there is required only one two-terminal inductance coil per section. The condensers .50, 50, etc.,

are connected by means of the brushes 5|, 5|, etc., to the ring I8, while the inductances 46, 66, etc., are connected together in series and are also connected at their junctions to the studs 52, 52,

etc.

Between the halves I! and I9 of the ring I8 there is an insulating element 53 which carries two conducting segments 54,, 55 spaced somewhat less than the width of the brushes 5| from the segments I9 and II, respectively, of the ring I8.

These segments 54 and 55 are connected to the segments I9 and I! through condensers 56 and 56 of the same capacity as the condensers 50.

Between the brushes t3 and 51 there is connected an inductance ll of the same value as the effective series inductance per section of line. Likewise between the brushes 51 and 44 there is connected an inductance 12 of the same value as the inductance The proper dimensions and spacing of the various brushes and contacts of the B-line switch as well as the manner in which the B-line adjustment is affected will be apparent from a consideration of Fig. 2.

In Fig. 2, a, b, c, d and e show successive posi tions of the switch from one section of the B- line to an adjacent section. In 2a it will be noted that the brushes 43, 51 and 44 and the contact elements i9 and 54, as well as 55 and II, are in such positions that both'parts of the line are terminated in the so-called mid-shunt manner since-the condensers 56 are in series with the condensers 50 to provide half the normal capacity at the ends of the lines. In the position indicated in b it will be noted that the left portion of the line is terminated in a mid-series manner while the right portion is still terminated in a mid-shunt manner. The mid-series termination of the left portion of the line is obtained by the parallel connection now existing between the inductance II and the inductance 46 whereby the effective inductance is one half of the normal inductance and the brush 5| now connects directly with element l9. In this manner one half of a section has been added to the left portion of the line while the right portion of the line remains the same. In position the left portion of the line still has a mid-series termination and the right portionof the line also receives a mid-series termination since the inductance I2 is now in parallel with the corresponding inductance 46' and the condenser 56 is no longer connected to brush 5|, thus terminating the right portion of the line in an inductance one half the normal inductance. In position d, it will be noted, the left portion of the line receives a mid-shunt termination while the right portion remains with a mid-series termination. In position e both portions of the line have mid-shunt terminations and the con ditions are the same as in position a, but advanced' one section to theright. V Fig. 2 illustrates the perfect terminationof the line in either a mid-shunt or a mid-series termination and further shows how the line is increased or decreased uniformly one-half sectionat a time.

To obtain the proper action, it will be evident from Fig. 2 that the brushes and contact studs must be given suitable relative dimensions. The position of the inner edges of brushes 43 and 44 is not critical, but 'the outer edges must be positioned a distance of 0.5P from the nearer edge of the center brush 51 (where P is the distance between centers of adjacent studs 52) since each bridging coil is in use one half the time. Likewise, the center brush 51 must have a width equal to the gap between two adjacent studs 52 plus 0.25? since a coil 46 is short-circuited one quarter of the time. It is also important to note thatthe coil switch and the condenser switch are so arranged with respect to each other that transi-, tions in one occur simultaneouslywith corresponding transitions in the other; for, example, when the brush 43 while moving toward the right in Fig. 2 leaves stud 52, the element 54 makes contact with one of the brushes 5|.

Brushes 44, 55 and studs 52; 5| are arranged in a similar manner, but in an opposite sense with respect to the direction of motion. Finally, it will also be observed that the right edge of 54 must and a common. The adjustment of the C-lines is not made by opening the common as in the case ,of the B-line, but by connecting to the junction points of the series inductances.

The brushes 62, 20, 63, and 64, 30, 65 divide each of the two C'lines into two parts, respectively. Inductances 58, 59, 65) and 6| are connected between the several brushes, as shown, in order that the parts of the C-Jines may be given proper terminations. The operation of the C-line ad- ,iustm'ent is indicated in Fig. 3 by the development of the switch controlling the left C-line.

In the position a the brushes 62, 63 are making connection with the contact studs 35 and 34, respectively. The inductances 58 and 59 each have an inductance of a value one half that of the effective series inductance per section of line. The

energy is taken oif the line through the brush 20;

which in position d connects to the line only through the inductances 58 and 59. If we suppose the energies entering at each end of the line arrive in phase at coil 13, then coil 13 will be at a current node. Under these conditions each half of the line will be terminated perfectly in a mid-- series manner by the coils 58 and 59.

In the prior art when a single brush was used, it was ordinarily made of suflicient width to connect at times simultaneously 'to two adjacent studs. When the direction of sound was such as to produce a current node in one coil, the proper setting of the switchwould short circuit this coil and the line would not be properly terminated. It will be apparent, however, that with the arrangement of the present invention, the C-line may be given perfect mid-series terminations.

Position b shows a transient position of the switch in which the line terminations are being changed from those in position a to those in position c. In position 0 the brush 20 contacts with the stud 34 while the brushes 62 and 63 are not connected to the line. The inductances 58 and 59 are therefore inoperative when the switch is in this position and both the left and the right parts of the line have a mid-shunt termination. The position d again shows a transient position of the brushes while position e is similar to position a but one section advanced to the right.

The proper width and spacing of the brushes with respect to the width and passing of the contact stud will be apparent from a consideration oi. Fig. 3; Each of the three brushes 62, 20 and 63 I has the same width b while the distance between them is the same as the width S of each of the studs 3| to 36'. Then if we let P be the distance between centers of adjacent studs and B be the total distance spanned by the three brushes, the following relations will hold: b=0.5P-S and B=1.5P-S. j

Fig. 4 shows a modification of the system shown in Fig. 3 for varying the length of a line such as the C-line without breaking the common. Here only two movable brushes 62' and 63' are employed. A single inductance coil 80 having a center tap 8| is permanently connected between them. This lead 8| corresponds to leads 21 or 28 of Fig. 1. The inductance coil 83 represents in a mid-series manner.

an ideal auto transformer. Its two halves must be tightly coupled. It should also have a high reactance as compared to the coil 16.

In position a; Fig. 4, the ends of the transformer 8B are shortcircuited so that theeflective impedance of each half. of 80 is zero. The efiect is, therefore, the same as though 8| were connected directly to stud 34 and each half of the line has a mid-shunt termination. In position b the switch is in a transient position. In position c the transformer 80 is in parallel with the coil 16. It can be shown that if 80 approaches an ideal transformer, as will be the case if its two halves are tightly coupled and it has a high reactance compared to coil 16, that in position c the lead 8! is eiiectively connected to the center of coil 'lfiso that each half of the line is now terminated a transient position, and position e is similar to postion a but one step advanced to the right.

In the system just described it is also important toobserve the correct dimensions of the brushes and contact studs as well as the spacing between them. If we let the width of each of the series of studs iii to 36. be S, the distance between centers of two adjacent studs be P, the width of each of the-brushes 62' and 63' be b and the totaldistance between the outer edges of the brushes 62' and 63 (that is, 2b plus the distance between 62' and 63') be B, we find that b=PS in order to make 'the transitions instantaneous and B =l.5PS in order to make the transitions equally spaced. 1

I The switching arrangement shown in Fig. 4 is in some respects superior to that shown in Fig. 3 since only two brushes are required.

Fig. 5 shows schematically an alternative manher of connecting the hydrophones and telephones to the retardation lines fromthat shown in Fig, 1. In the embodiment described in Fig. 1

the C-lines are shown as feeding to the center of the B-line through the brushes 43, 51 and 44 while the telephones are connected to the ends of the B- line. It will be obvious, however, that the opposite system may be employed if desired. This is shown in Fig. 5. In this figure the C-lines feed to the ends of the B-line and the telephones are connected to the center of the B-line through the brushes 43, 51 and M. An important difference between the two is that with the latter arrangement the two C-lines must have separate commons.. On the other hand, if separatev commons are used, the telephone transformers 88 and 69, Fig. 1, may be omitted as shown in Fig. 5. i

In any case, it will be apparent, of course, that microphones may be employed instead of magnetophones. However, if microphones are used, it will. generally be preferable to connect .them to the compensator through transformers rather than directly.

In prior practice on account of the 'fact that the B-line sections could not be halved in'making switch adjustments, the sections themselves had to be made half the size and this was not only expensive but increased substantially the bulk of the compensator. The use of the system described in my copending application Serial No. 600,191 allowed both the F. and C-lines and the .B-lines to be made of the same size sections, the size of the sectionbeing such that a half section corresponds to one step-of the switch elements. The efiect of this arrangement was to reduce the number of condensers.

Inthe present invention, on the other hand, the size of the inductance units in the B-line may be water inches.

Position d again shows r increased since only a single unit is required for each section. Thus the number of inductance coils required is also reduced, whereby manufacture is simplified.

The allowable size of section of the B-line is determined by the accuracy of observation of the binaural method or by the minimum perceptible difierence in the maximum method of observation, and the spacing of the hydrophones. Usually the size of a section is approximately 1.8

In the present case I may use a section having about 3 water inches retardation and may also use the same site section for the C- line. In the present invention the B-, C- and F-lines have the same cutoff frequency and have their impedances rather well matched and absolutely matched under the same conditions of termination of the B- and C-lines. 7 W

When the compensator is used for the maximum method the switch 10 must be closed. This switch connects the secondaries of the transformers 68 and 69 in parallel for the maximum method. The primaries of the transformers 68 and 6!! are matched to the line. The transformers may be omitted if it is desired only to use the binaural method or if, as above described, the C- lines have separate commons.

While the invention has been described above as applied to a compensator for use in systems for finding the direction of a source of sound waves, it will be apparent that it has other applications. Furthermore, it is useful not only in connection with retardation lines having series inductances and shunt capacitances, but also with other types of artificial lines or series of electrical structures. It should be noted that the line may be composed of impedances in any form including mutual inductance if desired and that the bridging elements may be impedances of any suitable form. The bridging elements and a switch of any of the types described may, for example, be used with a lattice line or with a line having series capacitances and shunt inductances. A still' further application is to attenuators in which resistances are used. In this case bridging resistors or an auto-transformer similar to the arrangement in Fig. 4 may be employed to give the effect of center-tapping the attenuator resistances. The invention may also be applied to the connection of loads with different sources of supply with or without retardation.

Accordingly, it will be appreciated that the present invention can be embodied in other forms and therefore I do not desire to limit myself to the embodiment herein described, but

I claim:

1. In an electric compensator having an arti- -flcial line comprising inductivei-series elements and capacitive shunt elements forming sections of the line and switching means including inductive and capacitive elements equal in magnitude to the inductive and ca acitive elements in the line and means for prog essively connecting said inductive and capacitive elements to add true half section steps to the line.

2. In an electric compensator having an artificial line comprising inductive series elements and capacitive shunt elements forming sections of the line and switching means including inductive and capacitive elements equal in magnitude to the inductive and capacitive elements in the line and means for progressively connecting said inductive and capacitive elements to add or remove true half section steps to the line.

3. In an electric compensator including an artificial line comprising inductive series elements and capacitive shunt elements forming sections of the line, switching means comprising a plurality of switch-contacts connected to the line at the ends of each section and a plurality of relatively moving contacts operatively associated therewith. a pair of inductive elements and capacitive elements equal respectively to the elements in the line and means connecting said inductive and capacitive elements to said movable switch contacts whereby the line may be'lengthened or shortened a true half section at a time.

4. In an electric compensator including an,

artificial line comprising inductive series elements permanently connected together and capacitive shunt elements connected at one side to points between said series elements, switching means including a plurality of groups of relatively fixed and movable contact elements, one of said groups of contact elements being connected to points in the line at the junction of said series elements and at the one end of the capacity shunts, the second group of said contact elements having associated therewith means for connecting said other shunt contacts in two separate groups and having associated therewith capacitive elements equal to the shunt capacitive elements connected at the extremities of the said last mentioned groups and means also associated with one of said other contact group for connecting inductive elements of equal magnitude between three successive contact elements connected between the series inductances in the line.

5. In an electric compensator. including an artificial line comprising inductive series elements and capacitive shunt elements, said inductive series elements being connected in series and said capacitive shunt elements being connected at one side to points between said series elements and switching means for effectively breaking the line at any desired point thereof, said switching means being provided with two inductive elements having terminals adapted to be shunted with any two successive series inductive elements of the line and a pair of capacitive elements having terminals adapted to be connected in series at points opposite said two inductive elements with said shunt elements in the line.

6. In an electric compensator including an artificial line comprising inductive series elements and capacitive shunt elements, said inductive series elements being connected in series and said capacitive shunt elements being connected at one ,Sid to points between said series elements and switching means for efiectively breaking the line at any desired point thereof, said switching means being provided with two inductive elements having terminals adapted to be shunted with any two successive series inductive elements of the line and a pair of capacitive elements having terminals adapted to be connected in series at points opposite said two inductive elements with said shunt elements in the line, said two inductive elements having inductances substantially equal to the series elements in the line.

'7. Inan electric compensator including an artificial line comprising inductive series elements and capacitive shunt elements, said inductive series elements being connected in series and said capacitive shunt elements being connected at one side to points between said series elements and switching means for effectively breaking the line at any desired point thereof, said switching means being provided with two inductive elements having terminals adapted to be shunted with any two successive series inductive elements of the line and a pair of capacitive elements having terminals adapted to be connected in series at points opposite said two inductive elements with said shunt elements in the line, said two capacitive elements having a capacitance substantially equal to the shunt capacitance elements in the line.

8. In an electric compensator including an artificial line'comprising inductive series elements having one end free and capacitive shunt elements forming a permanently connected line and switching means for efiectively opening said line including a common conducting element having a break therein for connecting the free ends of said shunt elements in two groups, said switching means also being provided with capacitance ing equal in magnitude to the inductive elements in the line.

9. In an electric compensator including an artificial line comprising inductive series elements having one end free and capacitive shunt elements forming a permanently connected line and switching means for efi'ectively opening said line including a common conducting element having a break therein for connecting the free ends of said shunt elements in two groups, said switching means also being provided with capacitance and inductive elements having terminals adapted to be parallelly disposed opposite the break in the common conducting element, said parallelly disposed capacitance and inductive elements being equal in magnitude to the inductive elements in the line, and external conducting leads connected to a point midway between the two parallelly disposed inductive shunt elements.

10. In an electric compensator having an artificial line comprising inductive series elements CERTIFICATE OF CORRECTION.

Patent No. 2,088,530. August 5, 1957.

LAURENCE BATCHELDER It is hereby certified that error appears in the printed specification "of the above numbered patent requiring correction as follows: Page 5, second column, 'lines 2h. and 59, claims 8 and 9 respectii rely", strike out the words "having one and free" and insert the same before 'forming" in lines 25 and 1+0, same claims; line 61, claim 10, for "two" read true; and that the said 7 Letters Patent should be readwi th these corrections therein that the same ma; conform to the record of the case in the" Patent Office. Signed and. sealed this 12th day of October, A. I 19-57,;

' I Henry van'Arsdale. Acting Commissioner of Patents. 

